The present disclosure relates to an image forming apparatus in which a fixing unit is provided in such a manner that it can be attached and detached to/from the apparatus main body, and in particular to an image forming apparatus including a height adjustment portion configured to adjust the height position of the fixing unit.
Conventionally, an image forming apparatus is provided with a fixing unit, wherein the image forming apparatus is a copier, a printer, a facsimile, or a multifunction peripheral, in which these functions are installed, or the like. The fixing unit includes: a heating roller in which a heater is embedded; and a pressure roller which is pressed against the heating roller. The pressure roller is rotatably supported by the casing of the fixing unit. In the state where the fixing unit has been attached to the apparatus main body of the image forming apparatus, the rotational driving force is transmitted from the apparatus main body to the heating roller. This causes the heating roller to rotate in a direction. When a transfer sheet passes through a nip portion between the heating roller and the pressure roller, the toner on the transfer sheet is fused by the heating roller, and an image drawn on the transfer sheet with the toner is fixed onto the transfer sheet.
This type of image forming apparatus is provided with a drive transmission mechanism, such as a motor, configured to transmit the rotational driving force to the heating roller of the fixing unit. The drive transmission mechanism is connected to an end of the rotation shaft of the heating roller in the state where the fixing unit has been attached to the apparatus main body.
In addition, there is known, as an example of the image forming apparatus, an image forming apparatus that is provided with a height adjustment mechanism configured to adjust the height position of the fixing unit attached to the apparatus main body. With this height adjustment mechanism, the parallelism of the heating roller and the conveying roller for conveying the transfer sheet can be adjusted with high accuracy.
The image forming apparatus is provided with a slide support mechanism for guiding the fixing unit to and supporting it at the attachment position. As an example of the slide support mechanism, there is known a rail support mechanism in which the fixing unit is horizontally slidably supported by rails or guide grooves that are provided at opposite ends of the fixing unit in the longitudinal direction (a direction matching the axis direction of the heating roller).